of chicago



Oct. 18,1927. 1,645.94l

R. T. LLlA S Patented Oct. 18, 1927.

UNETEE) STATES PATENT OFFICE.

RALPH T. WILLIAMS OF CHICAGO, ILLINOIS, ASSIGNOR TO BODINE ELECTRIC COM- PANY, OF CHICAGOILLINOIS, A CORPORATION OF ILLINOIS.

. Application filed' October -6, 1926. Serial, No. 139,905.

My invention relates to inductances of the class commonly employed as-radio tuningcoils, and to means for supporting such inductances. i

In someof its general objects, .my invention providesa-n inductance oofthis class which' will ainp-lify with fair uniformity over 'a wide range of-wave length, such las the entire rangenow employed by broadcasting stations; which. will int-roduce a quite low loss; which will. be zquite compact, and 'in which the Vresultingl magnetic: field fwill be so.. ooncentratedz that. the inductan'cel can easily be shielded from other inductances and against outside influences. i H .i

vIn some further aspects, my invention provides:aninductance which can readily besupportedjfrom a. part of the inductance spaced from the major 'portions of the inductance winding, and 'which can i'eadily be used, in a compact tandemarrangementzto atford a .ticl{ler coil. It also provides an indu'ctance winding:particularly adapted for theconvenient supporting and .rotating of the inductance, and one-in which the part of the winding which facilitates such supporting is arranged so as to reduce the longitudinal .diinension' of the inductance and so as to permit contigui'ty of the consecutive wire portions in each of the two main parts :f the inductance.

More particularly, my invention provides an inductance -consisting of two parallel coils connected by crossecl wire portions in igure 8 formation, with the consecutive turns in each coil contiguous and with the height of the cross-connecting wire portions equal to that of each coil. For this purpose, my invention provides a novel arrangement of these cross-connecting wire portions7 a novel method of winding the enti re inductance; and provides a novel disposition of the wire parts which form each of a plurality of connterpart and 'superposed Sections of the inductance, whereby the two main coils are wound in opposite directions as inductances whose magnetic fields reinforce each other, and whereby parts of the connections between these main coils form a non-inductance interposed coil.

gFurthermore7 my invention provides a novel and easily att-ached mounting for supporting such an inductance and for supporting the needed wire terminals. Still further and also more detailed objects will appear from the following specification and from the accompanying drawings, in which drawings Fig. 1 is an elevation of a radio tuning inductance embodying my invention.

` Fig..2 is a plan view of the same.

iFig. 3'is a plan-view of the same'inductancebefore the support and the Wire terminalstareattached 'to it." w I.

Figfi. 'isj en? eleretion'of 'the S'upprting and termiaalfcarrying lilmb'Pj-h fafdi f-uningfcqilfof-1gs- 1.,.an1v;2,:aknzztt right anales .tQ'j'Fig-l'l-.f J'; 1 y F ig. v5 is a diagrammatic ;viewshowing-t-he winding of one of the .superposed 'land cou'nterpart coil secti ons, With thefinandrel on which the Wire i wund shown 'in section.

Figs. 6,7, 8and 9 are diagrams respectively showing theconsecutiveparts of the coil section` o f Fig.f 5. u Z" i.

Fig. 10 is 'a pers'p'eictiveview of a tickle'r coil enihodyinginyjinvention.i' l j While 'thewinductances Z:of my invention may be employed with equal advantage for a largefvariety'of purposes, it is particularly adapted for use as a radiofrequency tuning coil or fora three-circuit tuning coil which employs atickler coil.` 'Hence I' tam illustratin'qr and describing my inventionin such embooiments although vI do not wish .to be limited to any particular employmentfof my invention.

Referring first to F ig. 5, this shows the two cylindrical mandrels 1 and 2 around which the main wire portions are wound with the direction of the winding around one mandrel opposite to 'that around the other manclrel, the two mandrels preferably being equal in diameter and having their axes parallel. In the ordinary figure 8 inductance as heretofore employed, the wire portions leading from each. mandrel to the other are disposed .as' straight tangents to both mandrels, so that these wire portions all intersect, along asingle axis parallel to the axes of the twormandrels, which axis of intersection is midway between the mandrel axes if the mandrels are of equal diameter. Consequently, there are two superposed crossed Wire portions at thisaxis of intersection for every complete figure 8 layer` of the winding. If the wires in the arcuate arts of the winding are conti Ious, the intersecting Wire portions will e double the heights of these arcuate parts which 'form the nrain' coils,` therehy doubling the hc-ighfof the inductance and the space :'0- qniret'` for it` and this same donhlefl hcight of the iinductanee will be nec-;led if the cen- -zecntive mainarcua'te 'Wire parts' of each coil are spaccd from each other to make the main eoils equal in height toth'e crossed connectinY Wire portions. In either case, the spacing of such wire parts'longitudinally of the -inductance reduces the eflicicncy of the inductance and doublcs the space occup'i'ed 'by the induetanee So also, if the consecutive arcuate wirc. parts of the n'iain coilsare co'ntiguous, so that. the ero'ssed write portions' excecd .the hcightof the main coils, the magnetic field gre'atly; (listifted; ,therby reducing the e'fiiciency of'the i-nduetane, making it more v dilicult to Shield the ;inductanc and'causini'distort'ions the periodic'curren't. wares. [O wiercenie' serious disadantages o'f'an oi'diiiai'y'ufigilre 8 Windirig'; interpose an intermediatemandijel'between the niain winding my rnducta'nee' ifritelihedi'ate inan'clrel is preferably,coiiidefrahly smaller in diameter than themaiidrelsfflfmd 2 and c'q'uidistant from theihainfiiiadielsy iii'd preferably has its axis parallel to Pand in -;ominon-plai`ie w ith 'the xesliofthe: niandrels.

Then wind7'tlie..yirelronnd the three mandrels in eoniiterpart'fsechioiis as -traced l;for o'ne' section.diagrainmatica-lly in Figs. (3 to 8 inclusive, and as shown icompositel'y in Fig. .,.,the Wire':porti'o'n'sv in 'Figiz 5 being slightly vspaiced. from4 the mandrels to avoid confusion :'Beginn'i'nfz'at the top'of the intermediatemandrel 3, I wind the Wire clockivise around :theman'drel 2,' and carry it under -thevintermediate mane'rel 3 as per (3. Then I 'wi'ndthe `wire counter-clocl{\\is: around the mandrel 1, pass itunder the vintermediate'ma'ndrel 3 as in Fig. 7, wind it clockwise around the. mandre'l 2 and again pass it above the intermediate lmandrel as shown in Fig. '8. For the final part of the section, I wind the wire counter-cloeluvise around the mandrel 1 andbring itover the top of. the mandrel 3 Or't-o the starting point of the winding as shown 'in "Figs. 5 and n thus u'inding each of the 'conntcrpart fire Sections which are superposed on each other longitudinally of the axes of the 'mardrels, and each of which sec't-io'ns includes two arcuate portions extending partly around one 'main nia-ndrel, the c'onne'ting wii'e portions vof the 'section are orosse'd 'at the four points designatcd in Fig. 5 'respectively as A? B, C- a-nd D. Thes`e four points are substantia-lly lat, the four Corners of a .square and are sp'aced'from each other snfhciently so that thewire parts between then'i can be be'nt out of the'g'eneral Plane of the wii-ein' that ,section of ft-he coil. Consequently, distributing't-he 'Wire crossin'gs.

in this manner and by eierting a suitable pressure on the Wire towards the previously wound portion (longitudinally of the axis of the inandrel 3) during the winding, I not only am able to have-the overlapping main areuate wire parts of the inductance contiguous, but-also can keep the height of the crossed Wire portions equal to the height of the said arcuate or main coil parts of the inductance.

By so doing, I can maliethe height (or axial length) of my inductance half of that required 'for the ordinary figure 8 coil in which the connect-ing wires all cross 'along a single axis, and can obtain conseeutively contigu'ous arcuate Wire portions of such a length extending a-pproximately 135 degrees around the a'x'is ofl each main mandrel--as to produce an inductance of low loss and high efliciency. So also, I avoidthe distorti-on of the magnetic' fild which oc'c'urs in an ordinary figurei'llic'oil 'when the ci'ossed wire portions vexceed the 'heirht ofthe main coil port-ionsfince winding's of my inductance are all di'spose'd a'pproximately lin planes atright angles'bo the .ax'es o'f'the main coils, so that these main coils'afford av closed magnetic circuit'as shown by the dotted linev 14 in Fi'g. 1, where-by the magnetic fluxes in the'two main colls reinforee each other; Owing to this closed magnieticacircuit-and to the ahsence'of adistort-ionl :of theriiag'netic field, I not only'make 'myindnetanceof high efieiency. but also prevent stray magnetic lin'es. tHen'ee my indctafnce requires comparatively little shielding.

Since the fiow of vcurrent through my inductance at any moment is either in the (lircction in which the Wire Iwas wound :or in a (l'irertion reverse to the winding, 'it will be crident from the drawings tha't'the flow of current th'roi'rgh the two main coils is in respectively oppositc direc'tions, 'hut 'is in one direction :throughout the length of each main coil. Howerer, in 'the interposed auxiliaxv coil 'then'flow off 'current at opposite sides of 'the hore 'of this coil is in opposite direct'ions` circumferentially of'this auxilinry coil. so thatrt'hese portions of the w-indinf:r neutraliye each other in their induct-ivc, effect. 'llcncc the intelposed anxiliary coil -is uon-inluctire and Will neithcrjdiStoF-t. the magnetic fieldof the 'main coils 'non-introv dncea considerable loss.

After a vccmtinuot'ls strand of insulat-ed wire'has been wound around the tl'l'rie'e man'- drels to form any desired number of 'superposed Sections each vdis'p'osetl *as fshow'n =in Fig. 5, the res'nlting ind'iiet'ance is -eas'ily ceinented into a'rigi'tl unitby 'applying-eollodion or the'like tothe arcuate-p'o'rtions of the coils an'd'the Wire c'r'osings at the'- points A and C after which'the 'completed inductance canvbe sli p'eti offv the m'an'drel's` TWhen thu's etac'lrd, the 'wineJ `po`rt1ons connecting the intersections A, B, C and D with one another form an interposed auxiliary tube (shown in Figs. 8 and 5 as .substantially octa-gonal'in section) which tube can be used to good advantage in mounting the inductance. For such a mounting, Fig. 4 shows an'insulating stem 5 of a length corresponding to theheight of the finished inductance coil and of' sucha diameter asto 'slide readi'ly into the'bore of the said auxiliary tube. A foot-piece G'is fastened to one end of the stem 5 by a screw 7 and 'hasperforations 8 for receiving screws by which it may be secured to any support; After-the 'stem 5=has been slid through' the'saidlauxilwire Sections woundv as shown in'Fig. v5, the

making of the needed fdoiiii'ections' toi'such c'oil parts being sowell'know'as 'to require no explan'ation or ill'us'tration here;

'Moreoverj my inductance'needfinot be stationary, as its ease of mounting'fand unusual compactness make it a'dv'anta'geous also"for use as a' rotatable'inductance. For'leirfample, two suchl inductances can readily be mounted with their axes in :alin'eme'nt and With one of them rotatable, thereby producing a very compact three-Circuit tuning coil, such as that shown in Fig. 10. "'In that case, I may clamp one inducta-nce to .a shaft extending through the bore of ahollow stem which supports the other inductance.

However, I do not wish to be limited either to a particular mounting for my novel inductance nor to the' details of the construction and arrangement above recited, since many changes might obviously be made without departing either from the 'spirit of my invention or from the appendcd claims.

I claim as my invention:

l. An inductance formed of a continuous wire wound to form two parallel tube portions of relatively reversed polarity connected by two intersecting pairs of crossed wire portions, the winding being such that the said crossed Wire portions form an intermedia-te tube having its axis extending parallel to the axes of the aforesaid tube portions.

2. An inductance formed of a continuous Wire wound to form two parallel main tube portions in which the direction of winding is relatively reversed, and two pairs of connecting Wire portions crossed so as to form 'a substantially quadrilateral intermediate tube, the .wire parts forming each of the two main tubeportions being 'contiguous and equal inVheight-to the joint height of the Wire portions forming the intermediatetube. z'

3;' An' induqtance asia peri'claim '1, in combination with 1a' supporting' member-extendmg through =the intermediate tube, :and

means associated zwith -the :supporting memberandengag'ing opposite 'ends of' the inter- Imediate 'tubeft'o clamp 'the intermediate `tube -f to fthe supporti'ngimember. v 4. ;Af'twinf'coil f inductance fformed' ofa continuous Wire-wound: to: *form twov .axially parallel tube' portions wound in'relatively reve'rse directions?R''onneetedr` by itwo? .inter- ,s'ectin'g pairs 'off ro'ss'edffwire portions; each of f the Isaid -fcro'ssed' Wire:v portions comprising 'tw`o sets* fof connecting Wire E'parts extending; inf'aicomm'on general direction, and the connecting wirewpartsZ of each set being Vbowedilaway from='those of the -otherL-setf in a direction transversei'ofa planefextending through 'the axes? off'bothi the 'said =itubef lportions? "11': '1'

5. An` inductancefiformed of a'continuous Wirey wound'V 'to form' `two 'parallel' and relatively l'spaced vmain 'tubes-v io'frelati'velyl fireversedff pola'rity connected by 'Wire portions which' also' 1 form 11a i smaller-di'ametered and "non-inductive' intermediate i tube having its axis parallel to'the 'a'xes'of the` 'said main tubes, the winding'being vsuchythat the conneting Wire portions intersect'- consecutively along four' axes consecutivelyspaced-circumferentially ofjthe'intermediate tube,

'6. An inductance formed of a'continuous wire wound to form two parallel and relatively'spaced main t-ubes connected by Wire portionsto a smaller-diameter intermediate tube which has its axis parallel to'the axes of the said main tubes, the winding being such that the current flows in opposite directions in the two main tubes, and so that the flow of current is relatively reversed in every two consecutively superimposed wire parts of the intermediate tube, whereby the said main tubes are of reversed olarity and the intermediate tube is non-in uctive.

7. An inductance formed of a continuous Wire wound to form two parallel main tube portions connected by two pairs of Wire portions crossed so as to form a substantially four sided intermediate tube, the winding being such that the current fiows in relatively opposite directions through the said main tube portions, and so that the fiow of current through opposite sides of the intermediate tube is in the same direction circumferentially of that tube.

8. An inductance composed of a continuous `:fire forined to ;'onstitute a pluralitgc of counterpart superposed Sections; each Surf cessix'e section comprising two superposetl figure 8 loops; .each section having the intersection of the Wire parts connect-img the bight-s of the upper loop spaeetl in the `general plane of the loop from the intersection of the Wire parts conrreeting the bights of the lower loop.

Ah irmuctanc-e formex of a icontinuous Wire wound substantially in figure 8 formation to form two 'parallel vand spacetl tubes; each tube rzi-ving a main piortion formed of contiguo-us Wire parts eorresponding in ransverse section to .more ,than half of a circie, the said ''i1:e plarts ofthe said main portions of the .two -tubes being-connected by connecting Wire portions which cross one .another to 'form :m intermediate ;tube having the cross-over points paee'd circumferentially of the intermediate tube, the saitl connecting Wire portions being bentsutficiently .out of the vgeneral planeofzthe said wire'parts .of the ,min' tube .portions ;which are connected by..t-hem,1so thatzthezintermediate tube is substan'ftlly equl. inl-height to the said spacedfi'tubes f 10. An inductancezcompringf acontinuous wincling formed of counterpart antliupenposed Sections; .eaeheotion-;eomprising two pairs ,of superposed-:ikrtd talinng -,are\ 1 a.- te Wire ,portionzithe windin'gof eachsuch ,pair

of arent-e pontions being an-;thef'opposite and repectively. contiguous to ert'uate wirc portions ofthe next lower section, antl in which the connecting ;wires are-kinkecl out. of the general lplzrnes of the arcuzite portions connected by them to make 'the said tube equai in height to the height of each set of superposed arcuate Wire parts.

12. An inclucta-nce comprising a continuous winding formed ,of eounterpzu't and superposecl ASections; each section comprising two pairs of superposed areuate Wire portion, the axes of .the sjid t \'o pairs being parallel and the two pairs'being connected by two pgiirs of 'connct-ing Wire pgrrt-s, the 'connecting Wzire'parts o5f -each-pair terminating at superpoed end of the zsaid ,arcuate parts,r eaoh pair of onnecting Wire parts extending in the generaldiirections of tangents ;to the said A: irciiate pzigts ,and intersecting the common plane of the axes of vall of the -gircuete. pgrnts, and =the. skail'generlal 'tlinpections of the-two pirof onnecting Wire .parts being ;at 2.111 :eee-le tO mh .otherous stran fof insnlteti' Wire, the Wire .p ortion eonneeting. thel rcuate lpart-spf these igned at 4Chicago, Illinois, September 27th,19 26; 4 i T TVILLIAMS. 

